Why didn’t NASA accept women astronauts until 1978? originally appeared on Quora, the place to gain and share knowledge, empowering people to learn from others and better understand the world. You can follow Quora on Twitter, Facebook, and Google Plus.

President Eisenhower directed NASA to select its astronauts exclusively from the ranks of military test pilots. This decision, while restricting the candidate pool, greatly simplified and accelerated the selection process. There were 508 potential candidates on the military rosters. 110 of those people met all of the qualifications. So that 110 was split into groups and invited to apply. There was no delay in the process to do security screenings, as all of the candidates had already been cleared by the military.

The first astronaut selected while not on military active duty was Neil Armstrong. He met the requirements because he had been a US Navy pilot and was a current test pilot. The test pilot requirement was removed for the third group of astronauts, although military jet fighter aircraft experience was still required. The first non-pilots selected were Astronaut Group 4 (The Scientists), in 1965. Each of them were required to complete a one year course of Air Force Undergraduate Pilot Training to become jet pilots.

The first class of astronauts selected to support the Space Shuttle program was the 1978 class. That class introduced the astronaut position of mission specialists. Mission specialists did not have to be career pilots. That class included the first female astronauts: Anna Fisher, Shannon Lucid, Sally Ride, Judith Resnik, Rhea Seddon, and Kathryn Sullivan.

The previous astronaut selection was in 1969 and wasn’t a true selection. It was a transfer of the US Air Force Manned Orbiting Laboratory astronauts to NASA, when that program was canceled.

It wasn’t until 1993 that the Defense Department relaxed the prohibition on women serving in combat aviation positions.

NASA’s first female Shuttle pilot was Eileen Collins. She had been the second female pilot to attend the US Air Force Test Pilot School. She first flew the Space Shuttle Orbiter in 1995. In 1999, she became the first female Space Shuttle Commander.

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